I bought a SMSL DO100 Pro based on a recommendation on some Reddit forum. It sounds like crap. I think it depends on your system and what you’re used to. I really wanted it to sound good and expected it to, but sadly the placebo effect wasn’t enough to overcome what my ears told me.
Was it “bad”? I think so. Did it literally damage my speakers or something? No, just an edginess and high frequency grain that made the music unenjoyable. I was just using my desktop system, a set of Focal Chorus 706 (which honestly pretty warm, I couldn’t even imagine using it with something more detailed and revealing).
I think you would need to define “bad” to have any reasonable chance at useful answers here. I’m kind of defining it as “I don’t think it sounds any better than what’s in my phone”, which may not mean “bad” per se, but I expected more for something that has an additional cost and is presumably meant to be plugged into a home stereo system.